This invention relates to an apparatus for removing a foreign matter, such as a stone or calculus in the choledochus and ureter, from within the human body cavity.
Conventionally, an incision is necessary to remove a stone or calculus in the narrow human body cavity or duct such as the choledochus. A recent advance of endoscope technique permits such a stone to be removed orally. The removal of a stone in the choledochus, for example, is effected as follows. As shown in FIG. 1, a duodenofiberscope 1 is lowered, from the mouth of the opening of a common bile duct 2 which is open through pappila vateri into the duodenum. The opening of the common bile duct 2 is cut and enlarged by an electrosurgical instrument 3 which is inserted thereinto through the channel of the duodenofiberscope 1. After withdrawing the instrument 3 from the duodenofiberscope 1, a sheath of a cage type stone removing device 5 is inserted, as shown in FIG. 2, through the channel of the duodenofiberscope 1 and the incised opening of the common bile duct 2 into that region of the choledochus 6 where a stone 7 to be removed is located. A cage or basket 8 of the stone removing device 5 is extended from the front end of the sheath and expanded. Then, the cage 8, together with the sheath, is withdrawn toward the opening of the bile duct 2. During withdrawal, the stone 7 is trapped in the cage 8 or held by the wires and removed from the choledochus 6.
As shown in FIG. 3, the cage type stone removing device 5 comprises the cage 8 and the sheath 10. The cage 8 comprises a plurality of spiral, elastic and flexible wires 9, a first connecting member 12 by which the front ends of the wires 9 are bundled, and a second connecting member 13 by which the rear ends of the wires 9 are bundled. To the connecting member 13 is connected the front end of an operating wire 11 which passes through the central bore of the sheath 10 and is reciprocably movable longitudinally of the sheath 10 when operated at the control section of the dudenofiberscope 1.
While the sheath 10 is being inserted into the intended portion of the choledochus 6, the cage 8 is received within the bore of the flexible sheath 10. After the insertion of the sheath is completed, the operating wire 11 is moved forwardly of the sheath 10, causing the cage 8 to be extended from the distal end of the flexible sheath 10 so that it expands, as shown in FIGS. 2 and 3, due to its elastic force. This permits the stone 7 to be trapped within the cage 8.
The above-mentioned operation applies to the removal of a stone in the other body cavity such as the ureter.
Suppose that under observation by an X-ray fluoroscope a stone removing operation is effected using a conventional stone removing device. In this case, the arrangement or configuration of the cage when it is extended from the sheath is determined by the position of the cage within the sheath and there is little possibility that the stone will be exactly situated between the adjacent trapping wires of the cage. If the stone rides on the wire of the cage, it is necessary to withdraw the cage into the sheath, make a suitable adjustment such as some rotation around the axis of the cage, and again extend it out of the sheath for stone removal. Such operations are cumbersome, time-consuming and undesirable from the standpoint of the protection of the body cavity. Furthermore, the bore of the sheath of the conventional cage type stone removing device is exclusively used for the reception of the cage and as a channel for the operating wire and it is not used for the other objects.